[deliverable/linux.git] / drivers / watchdog / mpcore_wdt.c

/*
 *	Watchdog driver for the mpcore watchdog timer
 *
 *	(c) Copyright 2004 ARM Limited
 *
 *	Based on the SoftDog driver:
 *	(c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
 *						All Rights Reserved.
 *
 *	This program is free software; you can redistribute it and/or
 *	modify it under the terms of the GNU General Public License
 *	as published by the Free Software Foundation; either version
 *	2 of the License, or (at your option) any later version.
 *
 *	Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
 *	warranty for any of this software. This material is provided
 *	"AS-IS" and at no charge.
 *
 *	(c) Copyright 1995    Alan Cox <alan@lxorguk.ukuu.org.uk>
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/io.h>

#include <asm/smp_twd.h>

struct mpcore_wdt {
	unsigned long	timer_alive;
	struct device	*dev;
	void __iomem	*base;
	int		irq;
	unsigned int	perturb;
	char		expect_close;
};

static struct platform_device *mpcore_wdt_pdev;
static DEFINE_SPINLOCK(wdt_lock);

#define TIMER_MARGIN	60
static int mpcore_margin = TIMER_MARGIN;
module_param(mpcore_margin, int, 0);
MODULE_PARM_DESC(mpcore_margin,
	"MPcore timer margin in seconds. (0 < mpcore_margin < 65536, default="
				__MODULE_STRING(TIMER_MARGIN) ")");

static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
	"Watchdog cannot be stopped once started (default="
				__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");

#define ONLY_TESTING	0
static int mpcore_noboot = ONLY_TESTING;
module_param(mpcore_noboot, int, 0);
MODULE_PARM_DESC(mpcore_noboot, "MPcore watchdog action, "
	"set to 1 to ignore reboots, 0 to reboot (default="
					__MODULE_STRING(ONLY_TESTING) ")");

/*
 *	This is the interrupt handler.  Note that we only use this
 *	in testing mode, so don't actually do a reboot here.
 */
static irqreturn_t mpcore_wdt_fire(int irq, void *arg)
{
	struct mpcore_wdt *wdt = arg;

	/* Check it really was our interrupt */
	if (readl(wdt->base + TWD_WDOG_INTSTAT)) {
		dev_crit(wdt->dev, "Triggered - Reboot ignored\n");
		/* Clear the interrupt on the watchdog */
		writel(1, wdt->base + TWD_WDOG_INTSTAT);
		return IRQ_HANDLED;
	}
	return IRQ_NONE;
}

/*
 *	mpcore_wdt_keepalive - reload the timer
 *
 *	Note that the spec says a DIFFERENT value must be written to the reload
 *	register each time.  The "perturb" variable deals with this by adding 1
 *	to the count every other time the function is called.
 */
static void mpcore_wdt_keepalive(struct mpcore_wdt *wdt)
{
	unsigned long count;

	spin_lock(&wdt_lock);
	/* Assume prescale is set to 256 */
	count =  __raw_readl(wdt->base + TWD_WDOG_COUNTER);
	count = (0xFFFFFFFFU - count) * (HZ / 5);
	count = (count / 256) * mpcore_margin;

	/* Reload the counter */
	writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD);
	wdt->perturb = wdt->perturb ? 0 : 1;
	spin_unlock(&wdt_lock);
}

static void mpcore_wdt_stop(struct mpcore_wdt *wdt)
{
	spin_lock(&wdt_lock);
	writel(0x12345678, wdt->base + TWD_WDOG_DISABLE);
	writel(0x87654321, wdt->base + TWD_WDOG_DISABLE);
	writel(0x0, wdt->base + TWD_WDOG_CONTROL);
	spin_unlock(&wdt_lock);
}

static void mpcore_wdt_start(struct mpcore_wdt *wdt)
{
	dev_info(wdt->dev, "enabling watchdog\n");

	/* This loads the count register but does NOT start the count yet */
	mpcore_wdt_keepalive(wdt);

	if (mpcore_noboot) {
		/* Enable watchdog - prescale=256, watchdog mode=0, enable=1 */
		writel(0x0000FF01, wdt->base + TWD_WDOG_CONTROL);
	} else {
		/* Enable watchdog - prescale=256, watchdog mode=1, enable=1 */
		writel(0x0000FF09, wdt->base + TWD_WDOG_CONTROL);
	}
}

static int mpcore_wdt_set_heartbeat(int t)
{
	if (t < 0x0001 || t > 0xFFFF)
		return -EINVAL;

	mpcore_margin = t;
	return 0;
}

/*
 *	/dev/watchdog handling
 */
static int mpcore_wdt_open(struct inode *inode, struct file *file)
{
	struct mpcore_wdt *wdt = platform_get_drvdata(mpcore_wdt_pdev);

	if (test_and_set_bit(0, &wdt->timer_alive))
		return -EBUSY;

	if (nowayout)
		__module_get(THIS_MODULE);

	file->private_data = wdt;

	/*
	 *	Activate timer
	 */
	mpcore_wdt_start(wdt);

	return nonseekable_open(inode, file);
}

static int mpcore_wdt_release(struct inode *inode, struct file *file)
{
	struct mpcore_wdt *wdt = file->private_data;

	/*
	 *	Shut off the timer.
	 *	Lock it in if it's a module and we set nowayout
	 */
	if (wdt->expect_close == 42)
		mpcore_wdt_stop(wdt);
	else {
		dev_crit(wdt->dev,
			 "unexpected close, not stopping watchdog!\n");
		mpcore_wdt_keepalive(wdt);
	}
	clear_bit(0, &wdt->timer_alive);
	wdt->expect_close = 0;
	return 0;
}

static ssize_t mpcore_wdt_write(struct file *file, const char *data,
						size_t len, loff_t *ppos)
{
	struct mpcore_wdt *wdt = file->private_data;

	/*
	 *	Refresh the timer.
	 */
	if (len) {
		if (!nowayout) {
			size_t i;

			/* In case it was set long ago */
			wdt->expect_close = 0;

			for (i = 0; i != len; i++) {
				char c;

				if (get_user(c, data + i))
					return -EFAULT;
				if (c == 'V')
					wdt->expect_close = 42;
			}
		}
		mpcore_wdt_keepalive(wdt);
	}
	return len;
}

static const struct watchdog_info ident = {
	.options		= WDIOF_SETTIMEOUT |
				  WDIOF_KEEPALIVEPING |
				  WDIOF_MAGICCLOSE,
	.identity		= "MPcore Watchdog",
};

static long mpcore_wdt_ioctl(struct file *file, unsigned int cmd,
							unsigned long arg)
{
	struct mpcore_wdt *wdt = file->private_data;
	int ret;
	union {
		struct watchdog_info ident;
		int i;
	} uarg;

	if (_IOC_DIR(cmd) && _IOC_SIZE(cmd) > sizeof(uarg))
		return -ENOTTY;

	if (_IOC_DIR(cmd) & _IOC_WRITE) {
		ret = copy_from_user(&uarg, (void __user *)arg, _IOC_SIZE(cmd));
		if (ret)
			return -EFAULT;
	}

	switch (cmd) {
	case WDIOC_GETSUPPORT:
		uarg.ident = ident;
		ret = 0;
		break;

	case WDIOC_GETSTATUS:
	case WDIOC_GETBOOTSTATUS:
		uarg.i = 0;
		ret = 0;
		break;

	case WDIOC_SETOPTIONS:
		ret = -EINVAL;
		if (uarg.i & WDIOS_DISABLECARD) {
			mpcore_wdt_stop(wdt);
			ret = 0;
		}
		if (uarg.i & WDIOS_ENABLECARD) {
			mpcore_wdt_start(wdt);
			ret = 0;
		}
		break;

	case WDIOC_KEEPALIVE:
		mpcore_wdt_keepalive(wdt);
		ret = 0;
		break;

	case WDIOC_SETTIMEOUT:
		ret = mpcore_wdt_set_heartbeat(uarg.i);
		if (ret)
			break;

		mpcore_wdt_keepalive(wdt);
		/* Fall */
	case WDIOC_GETTIMEOUT:
		uarg.i = mpcore_margin;
		ret = 0;
		break;

	default:
		return -ENOTTY;
	}

	if (ret == 0 && _IOC_DIR(cmd) & _IOC_READ) {
		ret = copy_to_user((void __user *)arg, &uarg, _IOC_SIZE(cmd));
		if (ret)
			ret = -EFAULT;
	}
	return ret;
}

/*
 *	System shutdown handler.  Turn off the watchdog if we're
 *	restarting or halting the system.
 */
static void mpcore_wdt_shutdown(struct platform_device *pdev)
{
	struct mpcore_wdt *wdt = platform_get_drvdata(pdev);

	if (system_state == SYSTEM_RESTART || system_state == SYSTEM_HALT)
		mpcore_wdt_stop(wdt);
}

/*
 *	Kernel Interfaces
 */
static const struct file_operations mpcore_wdt_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.write		= mpcore_wdt_write,
	.unlocked_ioctl	= mpcore_wdt_ioctl,
	.open		= mpcore_wdt_open,
	.release	= mpcore_wdt_release,
};

static struct miscdevice mpcore_wdt_miscdev = {
	.minor		= WATCHDOG_MINOR,
	.name		= "watchdog",
	.fops		= &mpcore_wdt_fops,
};

static int mpcore_wdt_probe(struct platform_device *pdev)
{
	struct mpcore_wdt *wdt;
	struct resource *res;
	int ret;

	/* We only accept one device, and it must have an id of -1 */
	if (pdev->id != -1)
		return -ENODEV;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res)
		return -ENODEV;

	wdt = devm_kzalloc(&pdev->dev, sizeof(struct mpcore_wdt), GFP_KERNEL);
	if (!wdt)
		return -ENOMEM;

	wdt->dev = &pdev->dev;
	wdt->irq = platform_get_irq(pdev, 0);
	if (wdt->irq >= 0) {
		ret = devm_request_irq(wdt->dev, wdt->irq, mpcore_wdt_fire, 0,
				"mpcore_wdt", wdt);
		if (ret) {
			dev_err(wdt->dev,
				"cannot register IRQ%d for watchdog\n",
				wdt->irq);
			return ret;
		}
	}

	wdt->base = devm_ioremap(wdt->dev, res->start, resource_size(res));
	if (!wdt->base)
		return -ENOMEM;

	mpcore_wdt_miscdev.parent = &pdev->dev;
	ret = misc_register(&mpcore_wdt_miscdev);
	if (ret) {
		dev_err(wdt->dev,
			"cannot register miscdev on minor=%d (err=%d)\n",
			WATCHDOG_MINOR, ret);
		return ret;
	}

	mpcore_wdt_stop(wdt);
	platform_set_drvdata(pdev, wdt);
	mpcore_wdt_pdev = pdev;

	return 0;
}

static int mpcore_wdt_remove(struct platform_device *pdev)
{
	platform_set_drvdata(pdev, NULL);

	misc_deregister(&mpcore_wdt_miscdev);

	mpcore_wdt_pdev = NULL;

	return 0;
}

#ifdef CONFIG_PM
static int mpcore_wdt_suspend(struct platform_device *pdev, pm_message_t msg)
{
	struct mpcore_wdt *wdt = platform_get_drvdata(pdev);
	mpcore_wdt_stop(wdt);		/* Turn the WDT off */
	return 0;
}

static int mpcore_wdt_resume(struct platform_device *pdev)
{
	struct mpcore_wdt *wdt = platform_get_drvdata(pdev);
	/* re-activate timer */
	if (test_bit(0, &wdt->timer_alive))
		mpcore_wdt_start(wdt);
	return 0;
}
#else
#define mpcore_wdt_suspend	NULL
#define mpcore_wdt_resume	NULL
#endif

/* work with hotplug and coldplug */
MODULE_ALIAS("platform:mpcore_wdt");

static struct platform_driver mpcore_wdt_driver = {
	.probe		= mpcore_wdt_probe,
	.remove		= mpcore_wdt_remove,
	.suspend	= mpcore_wdt_suspend,
	.resume		= mpcore_wdt_resume,
	.shutdown	= mpcore_wdt_shutdown,
	.driver		= {
		.owner	= THIS_MODULE,
		.name	= "mpcore_wdt",
	},
};

static int __init mpcore_wdt_init(void)
{
	/*
	 * Check that the margin value is within it's range;
	 * if not reset to the default
	 */
	if (mpcore_wdt_set_heartbeat(mpcore_margin)) {
		mpcore_wdt_set_heartbeat(TIMER_MARGIN);
		pr_info("mpcore_margin value must be 0 < mpcore_margin < 65536, using %d\n",
			TIMER_MARGIN);
	}

	pr_info("MPcore Watchdog Timer: 0.1. mpcore_noboot=%d mpcore_margin=%d sec (nowayout= %d)\n",
		mpcore_noboot, mpcore_margin, nowayout);

	return platform_driver_register(&mpcore_wdt_driver);
}

static void __exit mpcore_wdt_exit(void)
{
	platform_driver_unregister(&mpcore_wdt_driver);
}

module_init(mpcore_wdt_init);
module_exit(mpcore_wdt_exit);

MODULE_AUTHOR("ARM Limited");
MODULE_DESCRIPTION("MPcore Watchdog Device Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
Commit	Line	Data
b9d36b85 RK	1	/*
	2	* Watchdog driver for the mpcore watchdog timer
	3	*
	4	* (c) Copyright 2004 ARM Limited
	5	*
	6	* Based on the SoftDog driver:
29fa0586	7	* (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
143a2e54	8	* All Rights Reserved.
b9d36b85 RK	9	*
	10	* This program is free software; you can redistribute it and/or
	11	* modify it under the terms of the GNU General Public License
	12	* as published by the Free Software Foundation; either version
	13	* 2 of the License, or (at your option) any later version.
	14	*
	15	* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
	16	* warranty for any of this software. This material is provided
	17	* "AS-IS" and at no charge.
	18	*
	19	* (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
	20	*
	21	*/
27c766aa JP	22
	23	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	24
b9d36b85 RK	25	#include <linux/module.h>
b9d36b85 RK	26	#include <linux/moduleparam.h>
b9d36b85 RK	27	#include <linux/types.h>
	28	#include <linux/miscdevice.h>
	29	#include <linux/watchdog.h>
	30	#include <linux/fs.h>
	31	#include <linux/reboot.h>
	32	#include <linux/init.h>
	33	#include <linux/interrupt.h>
d052d1be	34	#include <linux/platform_device.h>
83ab1a53	35	#include <linux/uaccess.h>
5a0e3ad6	36	#include <linux/slab.h>
98af0570	37	#include <linux/io.h>
ad4162f3	38
98af0570	39	#include <asm/smp_twd.h>
b9d36b85 RK	40
	41	struct mpcore_wdt {
	42	unsigned long timer_alive;
	43	struct device *dev;
	44	void __iomem *base;
	45	int irq;
	46	unsigned int perturb;
	47	char expect_close;
	48	};
	49
aa065770	50	static struct platform_device *mpcore_wdt_pdev;
98af0570	51	static DEFINE_SPINLOCK(wdt_lock);
b9d36b85 RK	52
	53	#define TIMER_MARGIN 60
	54	static int mpcore_margin = TIMER_MARGIN;
	55	module_param(mpcore_margin, int, 0);
83ab1a53 AC	56	MODULE_PARM_DESC(mpcore_margin,
	57	"MPcore timer margin in seconds. (0 < mpcore_margin < 65536, default="
	58	__MODULE_STRING(TIMER_MARGIN) ")");
b9d36b85	59
86a1e189 WVS	60	static bool nowayout = WATCHDOG_NOWAYOUT;
86a1e189 WVS	61	module_param(nowayout, bool, 0);
83ab1a53 AC	62	MODULE_PARM_DESC(nowayout,
	63	"Watchdog cannot be stopped once started (default="
	64	__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
b9d36b85 RK	65
	66	#define ONLY_TESTING 0
	67	static int mpcore_noboot = ONLY_TESTING;
	68	module_param(mpcore_noboot, int, 0);
a77dba7e WVS	69	MODULE_PARM_DESC(mpcore_noboot, "MPcore watchdog action, "
	70	"set to 1 to ignore reboots, 0 to reboot (default="
	71	__MODULE_STRING(ONLY_TESTING) ")");
b9d36b85 RK	72
	73	/*
	74	* This is the interrupt handler. Note that we only use this
	75	* in testing mode, so don't actually do a reboot here.
	76	*/
7d12e780	77	static irqreturn_t mpcore_wdt_fire(int irq, void *arg)
b9d36b85 RK	78	{
	79	struct mpcore_wdt *wdt = arg;
	80
	81	/* Check it really was our interrupt */
	82	if (readl(wdt->base + TWD_WDOG_INTSTAT)) {
77e0dfcc	83	dev_crit(wdt->dev, "Triggered - Reboot ignored\n");
b9d36b85 RK	84	/* Clear the interrupt on the watchdog */
b9d36b85 RK	85	writel(1, wdt->base + TWD_WDOG_INTSTAT);
b9d36b85 RK	86	return IRQ_HANDLED;
b9d36b85 RK	87	}
b9d36b85 RK	88	return IRQ_NONE;
	89	}
	90
	91	/*
	92	* mpcore_wdt_keepalive - reload the timer
	93	*
	94	* Note that the spec says a DIFFERENT value must be written to the reload
	95	* register each time. The "perturb" variable deals with this by adding 1
	96	* to the count every other time the function is called.
	97	*/
	98	static void mpcore_wdt_keepalive(struct mpcore_wdt *wdt)
	99	{
98af0570	100	unsigned long count;
b9d36b85	101
98af0570	102	spin_lock(&wdt_lock);
b9d36b85	103	/* Assume prescale is set to 256 */
98af0570 SK	104	count = __raw_readl(wdt->base + TWD_WDOG_COUNTER);
	105	count = (0xFFFFFFFFU - count) * (HZ / 5);
	106	count = (count / 256) * mpcore_margin;
b9d36b85 RK	107
	108	/* Reload the counter */
	109	writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD);
b9d36b85	110	wdt->perturb = wdt->perturb ? 0 : 1;
83ab1a53	111	spin_unlock(&wdt_lock);
b9d36b85 RK	112	}
	113
	114	static void mpcore_wdt_stop(struct mpcore_wdt *wdt)
	115	{
83ab1a53	116	spin_lock(&wdt_lock);
b9d36b85 RK	117	writel(0x12345678, wdt->base + TWD_WDOG_DISABLE);
	118	writel(0x87654321, wdt->base + TWD_WDOG_DISABLE);
	119	writel(0x0, wdt->base + TWD_WDOG_CONTROL);
83ab1a53	120	spin_unlock(&wdt_lock);
b9d36b85 RK	121	}
	122
	123	static void mpcore_wdt_start(struct mpcore_wdt *wdt)
	124	{
77e0dfcc	125	dev_info(wdt->dev, "enabling watchdog\n");
b9d36b85 RK	126
	127	/* This loads the count register but does NOT start the count yet */
	128	mpcore_wdt_keepalive(wdt);
	129
	130	if (mpcore_noboot) {
	131	/* Enable watchdog - prescale=256, watchdog mode=0, enable=1 */
	132	writel(0x0000FF01, wdt->base + TWD_WDOG_CONTROL);
	133	} else {
	134	/* Enable watchdog - prescale=256, watchdog mode=1, enable=1 */
	135	writel(0x0000FF09, wdt->base + TWD_WDOG_CONTROL);
	136	}
	137	}
	138
	139	static int mpcore_wdt_set_heartbeat(int t)
	140	{
	141	if (t < 0x0001 \|\| t > 0xFFFF)
	142	return -EINVAL;
	143
	144	mpcore_margin = t;
	145	return 0;
	146	}
	147
	148	/*
	149	* /dev/watchdog handling
	150	*/
	151	static int mpcore_wdt_open(struct inode inode, struct file file)
	152	{
aa065770	153	struct mpcore_wdt *wdt = platform_get_drvdata(mpcore_wdt_pdev);
b9d36b85 RK	154
	155	if (test_and_set_bit(0, &wdt->timer_alive))
	156	return -EBUSY;
	157
	158	if (nowayout)
	159	__module_get(THIS_MODULE);
	160
	161	file->private_data = wdt;
	162
	163	/*
	164	* Activate timer
	165	*/
	166	mpcore_wdt_start(wdt);
	167
	168	return nonseekable_open(inode, file);
	169	}
	170
	171	static int mpcore_wdt_release(struct inode inode, struct file file)
	172	{
	173	struct mpcore_wdt *wdt = file->private_data;
	174
	175	/*
	176	* Shut off the timer.
5f3b2756	177	* Lock it in if it's a module and we set nowayout
b9d36b85	178	*/
83ab1a53	179	if (wdt->expect_close == 42)
b9d36b85	180	mpcore_wdt_stop(wdt);
83ab1a53	181	else {
77e0dfcc JP	182	dev_crit(wdt->dev,
77e0dfcc JP	183	"unexpected close, not stopping watchdog!\n");
b9d36b85 RK	184	mpcore_wdt_keepalive(wdt);
	185	}
	186	clear_bit(0, &wdt->timer_alive);
	187	wdt->expect_close = 0;
	188	return 0;
	189	}
	190
83ab1a53 AC	191	static ssize_t mpcore_wdt_write(struct file file, const char data,
83ab1a53 AC	192	size_t len, loff_t *ppos)
b9d36b85 RK	193	{
	194	struct mpcore_wdt *wdt = file->private_data;
	195
b9d36b85 RK	196	/*
	197	* Refresh the timer.
	198	*/
	199	if (len) {
	200	if (!nowayout) {
	201	size_t i;
	202
	203	/* In case it was set long ago */
	204	wdt->expect_close = 0;
	205
	206	for (i = 0; i != len; i++) {
	207	char c;
	208
	209	if (get_user(c, data + i))
	210	return -EFAULT;
	211	if (c == 'V')
	212	wdt->expect_close = 42;
	213	}
	214	}
	215	mpcore_wdt_keepalive(wdt);
	216	}
	217	return len;
	218	}
	219
42747d71	220	static const struct watchdog_info ident = {
b9d36b85 RK	221	.options = WDIOF_SETTIMEOUT \|
	222	WDIOF_KEEPALIVEPING \|
	223	WDIOF_MAGICCLOSE,
	224	.identity = "MPcore Watchdog",
	225	};
	226
83ab1a53 AC	227	static long mpcore_wdt_ioctl(struct file *file, unsigned int cmd,
83ab1a53 AC	228	unsigned long arg)
b9d36b85 RK	229	{
	230	struct mpcore_wdt *wdt = file->private_data;
	231	int ret;
	232	union {
	233	struct watchdog_info ident;
	234	int i;
	235	} uarg;
	236
	237	if (_IOC_DIR(cmd) && _IOC_SIZE(cmd) > sizeof(uarg))
795b89d2	238	return -ENOTTY;
b9d36b85 RK	239
	240	if (_IOC_DIR(cmd) & _IOC_WRITE) {
	241	ret = copy_from_user(&uarg, (void __user *)arg, _IOC_SIZE(cmd));
	242	if (ret)
	243	return -EFAULT;
	244	}
	245
	246	switch (cmd) {
	247	case WDIOC_GETSUPPORT:
	248	uarg.ident = ident;
	249	ret = 0;
	250	break;
	251
0c06090c WVS	252	case WDIOC_GETSTATUS:
	253	case WDIOC_GETBOOTSTATUS:
	254	uarg.i = 0;
	255	ret = 0;
	256	break;
	257
b9d36b85 RK	258	case WDIOC_SETOPTIONS:
	259	ret = -EINVAL;
	260	if (uarg.i & WDIOS_DISABLECARD) {
	261	mpcore_wdt_stop(wdt);
	262	ret = 0;
	263	}
	264	if (uarg.i & WDIOS_ENABLECARD) {
	265	mpcore_wdt_start(wdt);
	266	ret = 0;
	267	}
	268	break;
	269
b9d36b85 RK	270	case WDIOC_KEEPALIVE:
	271	mpcore_wdt_keepalive(wdt);
	272	ret = 0;
	273	break;
	274
	275	case WDIOC_SETTIMEOUT:
	276	ret = mpcore_wdt_set_heartbeat(uarg.i);
	277	if (ret)
	278	break;
	279
	280	mpcore_wdt_keepalive(wdt);
	281	/* Fall */
	282	case WDIOC_GETTIMEOUT:
	283	uarg.i = mpcore_margin;
	284	ret = 0;
	285	break;
	286
	287	default:
795b89d2	288	return -ENOTTY;
b9d36b85 RK	289	}
	290
	291	if (ret == 0 && _IOC_DIR(cmd) & _IOC_READ) {
	292	ret = copy_to_user((void __user *)arg, &uarg, _IOC_SIZE(cmd));
	293	if (ret)
	294	ret = -EFAULT;
	295	}
	296	return ret;
	297	}
	298
	299	/*
	300	* System shutdown handler. Turn off the watchdog if we're
	301	* restarting or halting the system.
	302	*/
aa065770	303	static void mpcore_wdt_shutdown(struct platform_device *pdev)
b9d36b85	304	{
aa065770	305	struct mpcore_wdt *wdt = platform_get_drvdata(pdev);
b9d36b85 RK	306
	307	if (system_state == SYSTEM_RESTART \|\| system_state == SYSTEM_HALT)
	308	mpcore_wdt_stop(wdt);
	309	}
	310
	311	/*
	312	* Kernel Interfaces
	313	*/
62322d25	314	static const struct file_operations mpcore_wdt_fops = {
b9d36b85 RK	315	.owner = THIS_MODULE,
	316	.llseek = no_llseek,
	317	.write = mpcore_wdt_write,
83ab1a53	318	.unlocked_ioctl = mpcore_wdt_ioctl,
b9d36b85 RK	319	.open = mpcore_wdt_open,
	320	.release = mpcore_wdt_release,
	321	};
	322
	323	static struct miscdevice mpcore_wdt_miscdev = {
	324	.minor = WATCHDOG_MINOR,
	325	.name = "watchdog",
	326	.fops = &mpcore_wdt_fops,
	327	};
	328
2d991a16	329	static int mpcore_wdt_probe(struct platform_device *pdev)
b9d36b85	330	{
b9d36b85 RK	331	struct mpcore_wdt *wdt;
	332	struct resource *res;
	333	int ret;
	334
	335	/* We only accept one device, and it must have an id of -1 */
aa065770	336	if (pdev->id != -1)
b9d36b85 RK	337	return -ENODEV;
b9d36b85 RK	338
aa065770	339	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
75f5a536 VK	340	if (!res)
75f5a536 VK	341	return -ENODEV;
b9d36b85	342
75f5a536 VK	343	wdt = devm_kzalloc(&pdev->dev, sizeof(struct mpcore_wdt), GFP_KERNEL);
	344	if (!wdt)
	345	return -ENOMEM;
b9d36b85	346
aa065770 VK	347	wdt->dev = &pdev->dev;
aa065770 VK	348	wdt->irq = platform_get_irq(pdev, 0);
60a1aa50 VK	349	if (wdt->irq >= 0) {
	350	ret = devm_request_irq(wdt->dev, wdt->irq, mpcore_wdt_fire, 0,
	351	"mpcore_wdt", wdt);
	352	if (ret) {
77e0dfcc JP	353	dev_err(wdt->dev,
	354	"cannot register IRQ%d for watchdog\n",
	355	wdt->irq);
60a1aa50 VK	356	return ret;
60a1aa50 VK	357	}
b9d36b85 RK	358	}
b9d36b85 RK	359
75f5a536 VK	360	wdt->base = devm_ioremap(wdt->dev, res->start, resource_size(res));
	361	if (!wdt->base)
	362	return -ENOMEM;
	363
aa065770	364	mpcore_wdt_miscdev.parent = &pdev->dev;
b9d36b85 RK	365	ret = misc_register(&mpcore_wdt_miscdev);
b9d36b85 RK	366	if (ret) {
77e0dfcc	367	dev_err(wdt->dev,
83ab1a53	368	"cannot register miscdev on minor=%d (err=%d)\n",
77e0dfcc	369	WATCHDOG_MINOR, ret);
75f5a536	370	return ret;
b9d36b85 RK	371	}
	372
	373	mpcore_wdt_stop(wdt);
aa065770 VK	374	platform_set_drvdata(pdev, wdt);
aa065770 VK	375	mpcore_wdt_pdev = pdev;
b9d36b85 RK	376
b9d36b85 RK	377	return 0;
b9d36b85 RK	378	}
b9d36b85 RK	379
4b12b896	380	static int mpcore_wdt_remove(struct platform_device *pdev)
b9d36b85	381	{
aa065770	382	platform_set_drvdata(pdev, NULL);
b9d36b85 RK	383
	384	misc_deregister(&mpcore_wdt_miscdev);
	385
aa065770	386	mpcore_wdt_pdev = NULL;
b9d36b85	387
b9d36b85 RK	388	return 0;
	389	}
	390
641e4f44	391	#ifdef CONFIG_PM
aa065770	392	static int mpcore_wdt_suspend(struct platform_device *pdev, pm_message_t msg)
641e4f44	393	{
aa065770	394	struct mpcore_wdt *wdt = platform_get_drvdata(pdev);
641e4f44 PF	395	mpcore_wdt_stop(wdt); /* Turn the WDT off */
	396	return 0;
	397	}
	398
aa065770	399	static int mpcore_wdt_resume(struct platform_device *pdev)
641e4f44	400	{
aa065770	401	struct mpcore_wdt *wdt = platform_get_drvdata(pdev);
641e4f44 PF	402	/* re-activate timer */
	403	if (test_bit(0, &wdt->timer_alive))
	404	mpcore_wdt_start(wdt);
	405	return 0;
	406	}
	407	#else
	408	#define mpcore_wdt_suspend NULL
	409	#define mpcore_wdt_resume NULL
	410	#endif
	411
f37d193c KS	412	/* work with hotplug and coldplug */
	413	MODULE_ALIAS("platform:mpcore_wdt");
	414
3ae5eaec	415	static struct platform_driver mpcore_wdt_driver = {
b9d36b85	416	.probe = mpcore_wdt_probe,
82268714	417	.remove = mpcore_wdt_remove,
641e4f44 PF	418	.suspend = mpcore_wdt_suspend,
641e4f44 PF	419	.resume = mpcore_wdt_resume,
b9d36b85	420	.shutdown = mpcore_wdt_shutdown,
3ae5eaec RK	421	.driver = {
	422	.owner = THIS_MODULE,
	423	.name = "mpcore_wdt",
	424	},
b9d36b85 RK	425	};
b9d36b85 RK	426
b9d36b85 RK	427	static int __init mpcore_wdt_init(void)
	428	{
	429	/*
	430	* Check that the margin value is within it's range;
	431	* if not reset to the default
	432	*/
	433	if (mpcore_wdt_set_heartbeat(mpcore_margin)) {
	434	mpcore_wdt_set_heartbeat(TIMER_MARGIN);
27c766aa	435	pr_info("mpcore_margin value must be 0 < mpcore_margin < 65536, using %d\n",
b9d36b85 RK	436	TIMER_MARGIN);
	437	}
	438
27c766aa JP	439	pr_info("MPcore Watchdog Timer: 0.1. mpcore_noboot=%d mpcore_margin=%d sec (nowayout= %d)\n",
27c766aa JP	440	mpcore_noboot, mpcore_margin, nowayout);
b9d36b85	441
3ae5eaec	442	return platform_driver_register(&mpcore_wdt_driver);
b9d36b85 RK	443	}
	444
	445	static void __exit mpcore_wdt_exit(void)
	446	{
3ae5eaec	447	platform_driver_unregister(&mpcore_wdt_driver);
b9d36b85 RK	448	}
	449
	450	module_init(mpcore_wdt_init);
	451	module_exit(mpcore_wdt_exit);
	452
	453	MODULE_AUTHOR("ARM Limited");
	454	MODULE_DESCRIPTION("MPcore Watchdog Device Driver");
	455	MODULE_LICENSE("GPL");
	456	MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);